Battery notes Battery runtime information is based on worldwide acknowledged BAPCO Mobile Mark 2007 Benchmark (readers mode e.g. surfing the internet, writing E-mails, viewing documents) which provides results that enable direct product comparisons between manufacturers. It does not guarantee any specific battery runtime which actually can be lower and may vary depending on product model, configuration, application and power management settings. The battery capacity slightly decreases with every charging cycle and over the lifetime.